This invention relates to a rotary index system of the type comprising a plurality of cards extending radially from a central rotatable drum.
In such a system, information is normally typed on the faces of the cards, and a desired card may be selected by rotating the drum until the card appears on the upper side of the drum. In order to read the information on the card, adjacent cards must normally be held out of the way to expose the face of the card. This normally requires the use of a hand although a typist, for example, will often place a pencil or other object between adjacent cards to separate them. To move on to the next card, in this case, the pencil is normally removed with one hand and the drum rotated with the other. It can be seen, therefore, that both hands are occupied, and when carrying out repetitive operations, such as typing addresses, this can slow the typist considerably.
Index systems of this type are known where each card carries a small magnetic strip to separate partially the cards. Such an arrangement allows the user to read the top of the card and facilitates the separation of the cards, but does not allow the reader to see the whole of the face of a card, owing to the large number of cards normally mounted on the drum.